Federal prosecutors don't want Barry Bonds' lawyers to argue that the government spent too much money in their seven-year probe of the former Giants outfielder's suspected use of steroids.

Bonds' lawyers, meanwhile, are eager to stop his former girlfriend from testifying about Bonds' temper - including an occasion on which he allegedly threatened to kill her.

In pre-trial filings made Monday, both sides asked trial Judge Susan Illston to set limits on the testimony and evidence that jurors can consider when baseball's home run champion goes to trial on perjury charges March 21 in U.S. District Court in San Francisco.

Bonds is accused of lying under oath in 2003 when he told a grand jury he had never knowingly used banned drugs. The testimony came during a federal investigation of the BALCO sports-doping scandal. Bonds has pleaded not guilty.

In their filing, prosecutors said they want to guard against "jury nullification" - a verdict based on sympathy rather than the evidence and the law. Prosecutors said Bonds' lawyers should be barred from telling the jury that "the prosecution spent too much money on this case," or that "all elite athletes use steroids" or that Bonds "has suffered sufficiently" from the stress of the probe and shouldn't be punished further.

Prosecutors also asked the judge to bar lawyer Michael Rains, one of six attorneys on the Bonds legal team, from testifying for his client.

Rains has complained that the government was out to get Bonds and set a "perjury trap" for the outfielder by refusing to let him view promised documents before he testified at the grand jury in 2003.

The prosecutors denied wrongdoing, and argued that the issue of alleged government misconduct is for the judge to consider, not the jury.

Bonds' lawyers said they don't want the government to present "personal invective, rumor and speculation" from witnesses who include "disgruntled ex-employees and a former girlfriend."

One witness of defense concern is Kimberly Bell, Bonds' former girlfriend. She has told investigators that Bonds confided to her that he used steroids.

She also says Bonds became more prone to sudden rages after that. The defense wants her to be barred from describing Bonds' alleged outbursts.

Prosecutors expect Bonds' team will cross-examine Bell about her decision to pose nude for Playboy magazine in 2006. Prosecutors asked the judge to bar Bonds' lawyers from showing the magazine to the jury.